This invention relates to a method of manufacturing a semiconductor device. More particularly, it relates to a method of forming an isolation region of the dielectric isolation type at a small width.
As the method of forming the isolation region of this type, there has heretofore been proposed a method wherein after forming a groove of V-shaped section in the surface of a semiconductor layer by the anisotropic etching, an insulating region (for example, a region consist of an insulating film and a polycrystalline silicon layer) is formed so as to fill up the groove. This method, however, has the disadvantage that since the open area of the V-shaped groove is considerably large, an enhancement in the density of integration is hindered.